Ram tube manifold for fuel injector on v-8 engine



8 1957 L. M. GOODRIDGE 2,801,620

RAM TUBE MANIFOLD FOR FUEL INJECTOR ON V-8 ENGINE Filed April 2, 1956 A 55 5e z r g I 4 .1: I 2' o is Q F I6. I

INVENTOR.

LAURENCE-M. GOODRIDGE ATTORNEY United States Patent RAM TUBE MANIFOLD FOR FUEL INJECTOR ON V-8 ENGINE Laurence M. Goodridge, Clayton, M0., assignor, by mesne assignments, to ACF Industries, Incorporated, New York, N. Y., a corporation of New Jersey Application April 2, 1956, Serial No. 575,512

6 Claims. (Cl. 123-52) This invention relates to an air induction system for a piston engine of the type having parallel rows of cylinders, and more specifically to such a system primarily for use with a fuel system which meters the required fuel and also performs the distribution function between cylinders through a flow path at least in part separate from the air induction system.

Where such a fuel system is used, the induction system is not depended upon to provide thenecessary even distribution of fuel between the cylinders, and its design should be one for utilizing the advantages to be derived from engine pulsations and dynamic flow for obtaining the best charging of the engine.

One way of obtaining these advantages has been to locate the individual carburetors adjacentthe engine intake ports and supply air to each carburetor by open ram tubes or air horns extending upwardly andoutwardly over the cylinder head of the opposite bank of cylinders. Such a system requires a separate throttle for each carburetor, which means eight throttles for a V-8 engine, and all throttles must be synchronized for satisfactory performance.

It is one of the objects of this invention to replace these prior constructions with an engine intake manifold which will obtain all the advantages of the ram tubes in the prior designs.

According to this invention, the air induction system is an engine intake manifold comprising a main air passage or header located between the parallel rows of cylinders below the valve covers, and a series of ram tubes which are closed at one end but open intermediate their length into the main air passage, and have open ends for connection with the intake ports for the cylinders.

Such a structure is compact and need not project above the height of the valve covers of. the engine; the need for individual throttles in each branch is avoided; and the benefit of ram pressure can be obtained. At this point it should be stated that the ram effect produced depends upon the tuned frequency of each ram tube. The shorter the tube, the higher the frequency. Thus, in order to obtain full benefit within the present range of engine speeds, the tubes should be as long as possible, because the best air pressure gain for engine charging occurs in the range of engine speeds in which the intake valve is open at the time the reflected sound wave from the closed end of the tube arrives. With short tubes extending only as far as the main air passage, this would be a very short time, indeed, and full benefit can be obtained only at very high engine speeds.

Further objects and advantages of this invention will appear from the detailed description of the structure illustrated in the accompanying drawings, in which:

Fig. l is a transverse vertical section taken on a line extending through the cylinders in opposite banks of a conventional V-8 engine.

Fig. 2 is a top plan view of an intake manifold according to the present invention.

Patented Aug. 6, 1957 ICC The invention is described as applied to one form of piston engine having opposite banks of cylinders. In this instance, the engine illustrated is one of the current V-8 engines used by the passenger car makers. It is contemplated, however, that the same principles applied here can be followed with any engine having parallel banks of cylinders.

It is the usual practice in V-8 engine design to cast both banks of cylinders within a single cylinder block, such as illustrated in Fig. 1 of the drawings. This view illustrates one cylinder in each bank of four cylinders. The left bank is illustrated as 1, and the right bank as 2. As shown, one bank is slightly offset ahead of the other, so that the connecting rods 3 and 4 may be attached to a single crank throw 5 of crankshaft 6 in side-by-side relation. Each connecting rod 3 and 4 carries a piston for driving the crankshaft 6 which, in turn, rotates a camshaft '7 carrying lobes 8, one for each intake and exhaust valve.

The cylinder ba'nkl has a cylinder head 10 to which is connected. an exhaust manifold 11. Likewise, the cylinder bank 2 has a cylinder head 12 secured thereon, to which is connected the exhaust manifold 13.

Within the cylinder heads 10 and 11 are a plurality of intake and exhaust valves, the latter of which are not shown. Each cylinder in the left bank has an intake valve, 15,, and each cylinder in the righthand bank has an intake valve 16. These, in turn, are operated from the camshaft 7by suitable valve gear such as indicated as 20 and 21. .Each intake valve controls an inlet port such as 24 and 25. The foregoing description relates strictly to the engine, which, in itself, forms no part of the present invention, and a further detailed description does not appear necessary for a full understanding of the present invention.

The induction system applied to the engine above described comprises an intake manifold having a central main passage or header 30, open at one end, located be tween the banks of cylinders and extending for the full length ofthe engine, at least. Communicating with the central air passage 30 are a plurality of ram tubes or air horns 31, 33, 35, and 37, which are connected with the inlet ports 24 in the left bank of cylinders. Each ram tube extends beyond the central air passage 30, terminating in a closed end, as illustrated at 41, 43, 45, and 47. Likewise, a plurality of similar ram tubes 32, 34, 36, and 38 communicate with the central passage 30 and extend downwardly to connect with the intake ports 25 in the right bank of engine cylinders. These ram tubes, in turn, also extend beyond the central air passage 30 and terminate in closed ends 42, 44, 46, and 48. In this particular form, the central air passage 33 is shown as a round tube, as is each of the ram tubes, but this showing is merly for the purpose of convenience, it being understood that the cross-sectional shape of the header and tubes used in the manifold is amatter of choice. The arrangement between the central air passage 30 and the ram tubes is such that communication between the two is established simply by an opening in one side of each of these tubes, respectively. As shown in Fig. l, a ram t'ube passes through an opening in the upper side of the central air passage 30 and has a similar opening in its lower side, but it is a continuous tube otherwise from intake port to closed end.

For purposes of illustration, the forward end of the main air passage or header 30 has been shown as provided with a simple throttle valve 50 controlled by an arm 51, which may be manually operated to control the amount of air. Since this induction system is principally intended for use with a fuel system which distributes the fuel to the cylinders, as well as measuring the proper quantity, such a fuel system has been schematically illustrated v V 3 Thesupply .ofiuel entering ,by way .of pipe .53 from the fuel tank and pump is metered within the casing 54 and distributed by way of pipes 55 and 56 to a plurality of nozzles 57,: 59, 61,4and 63 .in .theileftbank, and auplurality of .mozzles, 60,262, (64, .and :66 in.:the:ri'ght ibank. Each nozzle is suitably;mounted withinithezupperiwall10f the ram tube andlprojects downwardly.towardzzanintake port;24t or .25 of the ,engine. During operation, eachI-Iam tube is.supplied with air fromthemain airzpassage or header 30 according to throttle position. There Will beino flow restrictionlbetweenihe header .andjtubes as long as the openings between the ramitubes and theuheader have an .areaequalto thatiofrthe ramltubes. "BecauSeofthe tangential arrangement of the :ramrztubes, the flowpath has no sharpiturnsto .createlosses in :flow energy.

When engine .operating .speed :reaches the range in .Whichthe intake valves are .each opened when the reflected sound'wavelreturnsiromlthe closed en'd of the ram tubes, againin charging. ainpressure is attained which will increase the:brakemeaneffectivepressure in the engine to increase engine output.

The system illustrated has vithelrnain air passage or header 30 symmetrically .arranged with respect to the longitudinal .centerline .of the engine, :but it is contemplated that other modificationsincluding asymmetrical location of this header come within the scope of thisinvention.

A certain structure has .been described herein which will fulfill all the objects .of thepresentinvention, but it I is contemplated that othermodifications will be obvious to those skilled in the art which :come within the scope of the invention as defined by the appended claims.

I claim:

1. An air induction system for apiston :engine of the type having parallel rows of cylinderscomprising,- in combination, an air header located between the-parallel rows of cylinders, a plurality of ram tubes closed at one end and opening intermediate their length into said header, open ends for said ram tubes for connection with the intake ports of the individual cylinders, and a throttle for controlling the admission of airto said header.

2. An air induction system for a piston engine of the type .having parallel rows .of cylinders comprising, in combination, a header located symmetrically between the parallel rows of cylinders below the engine valve covers, a series of ram tubes closed at one end and opening into the header intermediate their length, each of said ram tubes having an open end'for connection with the intake port .ofa cylinder, and means for closing the opposite ends of said ram tubes.

3. An air induction system for a piston engine of the type havin parallelrows of cylinders comprising, :in combination, a header loeatedbetween said parallel rows of cylindersbelow the engine valve covers, a plurality of ram tubes having open ends connected with the intake ports of said engine and closed ends extending toward said opposite bank-of cylinders in tangential relation with said header, means forming interconnected openings between said ram tubes and said header, and throttle means for controlling the flow of air through each of saidram tubes.

4. An air induction system for a piston engine of the type having parallel rows of cylinders comprising, in com- .bination, an air header located between said parallel rows of cylinders, a plurality of ram tubes having open ends connected with the intake ports of one bank of cylinders of said engine and extending through and beyond said air header to closed ends adjacent the opposite bank of cylinders of .said engine, and openings in said ram tubes communicating with said air header.

5. The combination defined in claim 4, including a throttle means for controlling the air flow through each .of said ram tubes. 7

6. An 'air induction system for Ia piston engine of the type having-a row of spaced cylinders comprising, in combination, a plurality of ram tubes havingopen ends connected with the intake ports of the cylinders of said engine and extending in the same direction to closed ends disposed a substantial distance outwardly of said engine, an air headerdisposed lengthwise of said engine, and openings in said ram tubes intermediate their length communicating with said air header.

No references cited. 

